NGINX Configuration explained

What is NGINX?

NGINX (pronounced “engine-x”) is a high-performance web server and reverse proxy server that has gained widespread popularity in the world of web development and deployment. Originally developed to solve the C10K problem (handling 10,000+ simultaneous connections), NGINX has evolved into a robust solution capable of serving static and dynamic content, load balancing, caching, and acting as a reverse proxy for HTTP, HTTPS, SMTP, and other protocols.

Why is NGINX popular?

Performance: NGINX is known for its exceptional performance and efficiency. It is designed to handle many concurrent connections and deliver content quickly, making it suitable for high-traffic websites and applications.

Scalability: NGINX’s architecture allows it to scale horizontally by distributing the load across multiple servers. It can also serve as a load balancer, distributing incoming requests to backend servers, and ensuring optimal resource utilization.

Flexibility: NGINX is highly flexible and can be used in various scenarios. It can serve as a web server, a reverse proxy, or caching server. Its modular architecture allows for easy customization and extensibility.

Security: NGINX offers robust security features, such as SSL/TLS termination, access control, and DDoS protection. It can act as a buffer between clients and backend servers, shielding the internal infrastructure from potential threats.

Easy Configuration: NGINX’s configuration syntax is straightforward and easy to understand. It uses a simple, declarative approach, making it accessible to both novice and experienced users.

With NGINX, a master process oversees multiple worker processes. The master process manages the workers, while the workers handle the actual request processing. Since NGINX is asynchronous, each worker can execute requests concurrently, ensuring that one request does not block others.

NGINX boasts several common features, including:

• Reverse proxy functionality with built-in caching
• Support for IPv6 protocol
• Load balancing capabilities for distributing traffic across servers
• FastCGI support, including caching for improved performance
• WebSockets support for real-time communication
• Efficient handling of static files, index files, and automatic indexing
• TLS/SSL support with Server Name Indication (SNI) for secure connections.

NGINX Configuration

The NGINX configuration files are typically located in the “/etc/nginx/” directory, with the main configuration file specifically named “nginx.conf”.

NGINX configuration options are referred to as “directives” and are organized into groups known as “blocks” or “contexts”.

Lines in the configuration file that begin with a “#” symbol are comments and are not interpreted by NGINX. Directives, on the other hand, should be terminated with a semicolon “;” to ensure proper configuration loading. Failure to include the semicolon will result in configuration errors.

In the provided “/etc/nginx/nginx.conf” file, there are four directives at the beginning, namely:

• user
• worker_processes
• error_log
• pid

These directives exist outside any specific block or context and are considered part of the main context.

Additional directives can be found within the “events” and “http” blocks, which are also within the main context.

The nginx.conf file is the main configuration file for NGINX. It contains directives that define how NGINX should behave and process incoming requests. Here are some key aspects of the nginx.conf file:

Contexts: Directives in the nginx.conf file are organized into different contexts, such as http, server, and location. Each context defines a specific level of configuration and provides a hierarchical structure for organizing directives.

HTTP Block: The http context is the top-level context in the nginx.conf file. It contains directives related to HTTP and serves as a container for server blocks.

Server Block: The server context defines the configuration for a specific server or virtual host. It includes directives such as listen (specifying the IP address and port), server_name (defining the domain name), and other server-specific settings.

Location Block: The location context allows you to define configuration rules for specific URL patterns. It is used to specify how NGINX should handle requests for different locations within a server.

Global Directives: The nginx.conf file also contains global directives that apply to the entire NGINX configuration. These directives set global options, define worker processes, and configure logging, among other things.

Worker Process: The number of worker processes in NGINX should ideally match the number of server cores. It can be set to “auto” to automatically utilize all available cores.

Worker Connections: NGINX is designed to handle multiple connections without blocking using a single-threaded worker. The “worker_connections” directive sets the maximum number of connections. In contrast to Apache, which uses one process per connection, NGINX can efficiently handle multiple connections with a single worker.

Dynamic vs. Static Modules: NGINX supports both dynamic and static modules. Static modules are deployed during installation, while dynamic modules, similar to Apache, can be compiled and added to a live server. It’s also possible to compile NGINX with the same Linux OS version on another server or PC.

Example NGINX configurations

Using the NGINX configuration generator

Conclusion